Countryside Corner; Neighborly Garden News

Issue 76
August 2018

Have you heard of Red Thread? Sorry, it is not a craft beer!

Red thread (Laetisaria fuciformis) is a fungal disease that can infect most species of turf grass we grow in our area. Weather conditions during late summer into fall are particularly favorable for disease development on susceptible lawns. Our office receives a lot of worried phone calls about the unusual red or pink circular patches forming seemingly overnight on lawns. The pathogen attacks the turf plant’s foliage; causing individual blades to die from the tip down. The lawn will have a mixture of dead and healthy leaves, giving it a diffuse, scorched, and ragged appearance.

Infected lawn with scorched appearance

The fungus spreads through structures called mycelium; comparable to vegetative growth in plants. You may observe the pink mycelium growing on leaf blades, during wet weather. Red thread will also produce sclerotia; hardened fungal tissue that act as the resting stage of the pathogen. The sclerotia resemble reddish-orange ‘threads’ that grow out of infected leaf blades, hence the common name. The sclerotia are easily detached and spread by equipment or foot traffic, and can remain viable and ready to re-infect for up to two years.

Close-up of infected patches

Red Thread sclerotia

Susceptibility to Red Thread is minimized through proper cultural practices, as L. fuciformis is most likely to occur on slow growing lawns; due to low fertility, lack of sunlight, and drought. Early control to lessen disease severity can sometimes be established by applications of water soluble nitrogen. It is important to maintain correct soil pH (6.0-6.5) in addition to providing a complete fertilizer. Fertilizer uptake in plants is greatly influenced by maintaining the correct soil pH for their species.

Prune and thin trees and shrubs that may be interfering with sun exposure and air circulation. It is difficult for grass to grow well in the shade. Shallow, frequent sprinkling does more harm than good, and wastes water. Water the lawn deeply and infrequently to promote a deep root system. It is better to water in the morning, rather than the evening, so you limit the amount of time the leaves stay wet, inhibiting the possibility of infection. If there is any disease present, collect and dispose of the grass clippings (Don’t compost!) to reduce the amount of sclerotia (infectious material) that may be spread.

August’s ‘to-do’ list:

It’s so important now to keep up with weeding chores. For each mature weed you pull now, saves you from weeding hundreds of seedling weeds later. Weeds steal food, water, space, from your favorite plants, so keep pulling them out! Preventing mature weeds from going to seed will save you hours of pulling next year.

Mid-August through mid-September is a great time for over-seeding and renovating your lawn. Take advantage of turf’s natural growth cycle; grass will become dormant through the hottest part of summer, and then revive as temperatures begin to cool, and steady rain starts again.

Continue planting cool weather loving crops for fall harvests. Stagger sowing your seeds every 10 days or so they won’t all be ready at once. Lettuce, arugula, spinach, radish, and even garden peas can be successfully grown as a fall crop. A fresh crop of young basil would be an excellent companion to the bounty of summer tomatoes available this month.

Stop fertilizing Roses this month so any new growth has time to harden off before the frost. This step can help reduce winter injury on your Rose plants; less to prune out next spring.

Dig and divide Peonies this month. Remember that the ‘eyes’, or dormant flower buds must be planted no deeper than 1-2” below the soil surface. Planting deeper than this will interfere with blooming.

Begin to make your houseplants ready for reintroduction to indoor life. Transplant into larger pots as needed, scout for insects and wash them off, before the plants come back indoors. An effective method is to apply a granular systemic insecticide directly to the soil. This way only the bad bugs will be killed, and the pesticide stays within the plant tissues.

Have the weeds taken over or do you need help with your late summer chores? We can help; give our office a call or email: info@countrysidelandscape.net

Managing weeds: drought doesn’t stop them!

We’ve had some abnormally dry weather conditions through most of the season, with some heavy downpours interspersed with hot daytime temperatures. You’d think that weeds would suffer as much as our garden plants. I’ve spent hours over the last few months watering the vegetable and perennial gardens; just to keep them thriving. In my yard I admit to turning a blind eye to some areas, and let them go a bit wild. Weeds have grown to massive size in un-irrigated areas, despite the hot and dry conditions. How do they manage to grow so well, with zero assistance?

Weeds have several survival strategies they utilize to stay alive; perennial type weeds often form a very deep tap root, that are also thick and substantial. This root system gives them the ability to draw moisture and nutrients from deep reserves. The bulky roots also store water and starches, allowing weeds to regenerate from the roots when we remove the leafy parts, without much harm to the weed plant.

During a droughty season weeds seeds may be delayed in emerging, or sprout erratically in very dry years. Sometimes weeds may sprout in flushes through the summer, as we receive intermittent rainfall over a growing season. This flexible germination routine enables a weed to survive almost every weather pattern Mother Nature can create.

Dry conditions also can affect how we utilize chemical weed control applications. Certain herbicides are aided by moisture enabling the herbicide to be taken up into the plant tissues. During prolonged dry spells, a plant’s leaf texture will modify to suit the environment; the leaf will produce a thickened cuticle layer to inhibit transpiration. This thickened cuticle can also inhibit absorption of herbicide into the leaf. Hot and dry conditions may create a physical barrier of dust and fine debris, which can prevent certain herbicides from making good contact with the weed’s leaves. Herbicides, like Glyphosate, can bind with the dust particles, and be rendered less effective too.

Another survival strategy weeds employ is drought escape. They will accelerate their life cycle to develop and mature before the drought becomes too prolonged. So when you thought you saw the weeds doubling their size overnight, you weren’t wrong! The weed will go on to survive the drought in a dormant stage, as seeds, tubers, or rhizomes, until conditions are favorable for growth again. Our best defense is still cultivating or removing weeds when they are small, and not allowing them to go to seed.

Thinking ahead…

I love my flower gardens. Hours of planning and care result in weeks of spectacular blooms. To be assured of getting the best performance from my plants, I try to pick mainstays that will bloom through adverse conditions and over as many weeks as possible. To this mix of sturdy plants, I add a lively assortment of annuals and my collection of tropical plants to create my unique garden space. Here are my recommendations for perennials that can take the heat (and drought) and bloom for at least four weeks.

Echinacea purpurea, although the common name of this native is ‘Purple Coneflower’, the most marketed varieties now are the fancy orange, pink or red flowered types. For hardiness and reliability, you can’t beat the cultivars Magnus or the petite ‘Kim’s Knee High’. Coneflowers do best in full sun, the tall types can grow 3-4 feet tall, dwarf cultivars can range 18-24” tall. Deer Resistant plant.

Echinacea ‘Magnus’

Echinacea Kims Knee High

Asclepias tuberosa, Butterfly Weed loves hot and dry garden beds. It is much loved and sought out by butterflies, especially Monarchs, hummingbirds, and bees. There are several cultivars available, so you can choose between yellow and orange varieties. Butterfly Weed is not fussy at all about soil type, but they do want a higher pH (7.0) than most plants. Asclepias tuberosa grows 2’ X 2’, needs at least 6 hours of sun daily, will bloom the whole summer if dead-headed; makes a good cut flower. Deer Resistant plant.

Asclepias tuberosa

Geranium cantabrigiense ‘Biokovo’, perennial Cranesbill has a lot going for it, for a diminutive plant. Growing only 6-12” tall, Biokovo blooms for weeks from late spring to early summer. The fragrant leaves form a tight mat, so this Geranium also makes a good ground cover, or front of the border plant. As an added bonus, the leaves blush brilliant red-purple in the fall. Geranium Biokovo will grow in full sun to mostly shade; including dry shade. Deer Resistant plant.

Geranium cantabrigiense ‘Biokovo’

Geranium cantabrigiense ‘Biokovo’

Perovskia atriplicifolia, Russian Sage is not a member of the Salvia or true sage family. It is related to mint, and has mildly aromatic silver foliage. Russian sage is sometimes called a sub-shrub, in that it will form a woody framework of branches each season, then die to the ground over winter. Perovskia will bloom from July through September, and neither heat, drought nor pests bother it, including deer. Russian Sage will grow 3-4’ tall, and requires full sun.